


Happy Birthday

by Intellusion



Category: Shingeki no Kyojin | Attack on Titan
Genre: Condoms, Consensual, F/M, Lemon, M/M, Shameless Smut, Threesome - F/M/M, canon-divergence
Language: English
Status: Completed
Published: 2014-02-10
Updated: 2016-04-11
Packaged: 2018-01-11 20:17:05
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings, Underage
Chapters: 3
Words: 3,520
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1177468
Author URL: https://archiveofourown.org/users/Intellusion/pseuds/Intellusion
Summary: <blockquote class="userstuff">
              <p>It is Jean's birthday today. Hmm, I wonder what everyone got him?</p>
            </blockquote>





	1. What to Get Him?

**Author's Note:**

> Warning: I have never written a fanfic/smut in my life, so here it goes. It might suck, it might not. Oh, and I wrote this at four in the morning. Forgive me.

"What did you guys get Jean?" Armin's eyes lit up as he tried to spark a conversation at the dinner table that consisted of the usual trio.

"What?" Eren looked up from his mashed potatoes that he had been playing with instead of eating.

"You didn't know? It's Jean's birthday today." Armin looked curiously at Mikasa, who had not said a word since dinner began.

"Oh, right." Eren smirked a little, throwing down his fork. "I got that bastard something: a knuckle sandwich." Eren balled his fists, remembering a brawl he had with Jean two days ago. Mikasa touched Eren's shoulder to calm him down, working slightly. Mikasa glanced over at Armin.

"I got him nothing." Mikasa uttered.

"Really? Wow, you guys are pretty insensitive." Armin eyed Mikasa. Something was different about her, but he could not pinpoint it. Armin turned his attention back to Eren who had not noticed Mikasa's strange behavior.

"Well, what did you get Horseface?" Eren snapped out of his fury and glanced over at Armin.

As the two boys began conversing, Mikasa stared at nothing. She thought about what she was going to get Jean, but considering she did not have the time or money, she was left with nothing. Nothing, but maybe a favor?

 

The bell that signaled for the trainees to head to their respected dorms had rung. Armin and Eren headed toward the men's bunk, leaving Mikasa. Being alone gave Mikasa time to think. Finally, she came to a conclusion on what to get Jean.

_I'll just give him a kiss,_ she thought to herself, _a simple kiss._ Mikasa knew how much Jean admired her, so this would be perfect. _Now all I have to do is find Jean. But where was Jean? He was not at dinner with the rest of the trainees._

"Hey," Mikasa stopped Sasha who was walking towards the female dorm, "Have you seen Jean? I didn't see him at in the mess hall during dinner."

"Hmm," Sasha stopped in her tracks with a thoughtful look on her face. "I think I saw him heading toward the maintenance room not that long ago, just before dinner." She pondered. "Why? Do you need him?"

"No, Eren was asking about him." Mikasa pulled her scarf up a little to shield her burning cheeks. Luckily, Mikasa's blush is unnoticeable to Sasha, who continues her walk to the barracks. When Sasha was out of sight, Mikasa turned her heel and headed toward the main training building.


	2. What Did I Just Find?

**Summary for the Chapter:**

> Mikasa hurried her pace toward the door of the maintenance room and stood still for a moment, gathering her thoughts. Just as she was about to turn the doorknob, she heard an incomprehensible whisper. Mikasa's interest peeked.
> 
> Things are definitely getting a lot hotter in the maintenance room.

_What is Jean doing in the maintenance room?_ Mikasa thought as she walked stealthily through the halls of the main building, trying to be as quiet as possible. _He can't be possibly fixing his three-dimensional gear at this time of night._

Mikasa stopped immediately when she heard footsteps coming. Quickly, she hid behind the corner, awaiting for an instructor to punish her for being out this late. But no, the footsteps sounded surprisingly distant as if they were heading towards the maintenance room. _Maybe that's Jean!_

Mikasa hurried her pace toward the door of the maintenance room and stood still for a moment, gathering her thoughts. Just as she was about to turn the doorknob, she heard an incomprehensible whisper. Mikasa's interest peeked.

Just open the door slowly and peak in, Mikasa told herself. In case it happened to be an instructor inside the room, she could easily close the door and bound toward the dorms safely. She finally gathered the courage to turn the doorknob softly and look in.

"Marco," A soft sound rose from Jean's mouth, lips having opened slightly. Jean's shirt and gear and shirt laid beside him on the ground while Marco was on top of him.

"Shh, someone might hear us." Marco put his fingers to his own lips. Marco's mouth then latched on to Jean's left nipple and gave it quick suck. He did the same to the other one, licking it seductively.

"But," Jean tensed up, "But no one is around." As Jean spoke, Marco undid Jean's zipper.

Mikasa's eyes widened at the scene before her. She let out a gasp, shocked at the two trainees. She quickly covered up her mouth, hoping she did not blow her cover.

Jean's body perked up at the noise, "What was that?" Marco instantly pushed himself up off of Jean to inspect.

Mikasa tried to shut the door with haste but was too late. Marco had yanked the doorknob, revealing her.

"So you're the culprit making all that noise?" Marco smirked.

"No!" Mikasa said defensively, "It's you two making all that racket!" Mikasa took a step back. "What are you guys doing here anyways?" Mikasa looked at Jean, who was still sitting on the ground with his pants unzipped.

"Isn't it obvious?" Marco shrugged teasingly, "I am giving Jean his birthday gift, and I want to know the same."

"Well, I-" Mikasa was taken aback by the interrogation, "I, um, was going to do the same." Her cheeks burned. _But only a kiss,_ she added in her mind. Marco perked up a little after hearing her answer, grabbing her hand.

"Then join in." Marco smiled at Mikasa, leading her toward Jean's seat. Marco playfully shoved Mikasa, making her fall into Jean's lap.

"Wait!" Jean snapped as Mikasa fell into his lap, looking at the two questioningly, "Mikasa too? I don't know about this." Jean's red cheeks matched Mikasa's.

"Oh you can do it, _Jean._ " Marco let Jean's name linger in his mouth provocatively.

"Stop!" Mikasa pushed herself away from Jean and faced Marco. Taking a few steps forward, Mikasa was away from ear shot of Jean. "I didn't agree to this." She whispered directly at Marco. Marco sighed.

"One second, Jean," Marco smiled before he pulled Mikasa to the side to speak with her, out of hearing distance of Jean. "I thought you said you wanted to give Jean a birthday present too?"

"I did, but not this kind of birthday present." Mikasa gestured toward Jean.

"What?" Marco gave her a confused look. Mikasa shook her head.

"I meant, I was only going to give him a kiss. I thought it was the least I could do since," Mikasa looked at Jean with pity, "you know, he likes me."

"Come on, Mikasa." Marco's voice grabbed her attention and looked back at Marco. "Please do this for Jean. I mean, it is his birthday after all. Why not spoil him a little bit?" Marco gave her an encouraging smile. Mikasa pouted while she considered.

"Damn you, Marco." Mikasa let out a sigh as she gave in to the convincing boy. Marco almost leaped with excitement. The two made their way back over to the bewildered Jean.

"So um," Jean scratched the back of his head, wondering what to do. Jean peered at the ground for a moment before looking up at Marco and Mikasa. Both of them had the same greedy smile painted on their faces.

Mikasa crawled back into Jean's lap with her back arched, her face so close to his. "What do you want, Jean?" Jean gawked at her in response.

"Come on Jean," Marco sauntered over behind Jean and bent down to grasp his shoulders. "Tell her what you want." Marco whispered those alluring words. Marco's breath was hot on Jean's ear.

"I want you to," Jean blushed surprisingly harder, "to take off your scarf." Mikasa did what she was told and took off her scarf as slowly as possible, teasingly.

"What next?" Marco whispered into Jean's ear again. Jean did not know the answer. Jean, along with Marco, looked at Mikasa for an answer. Mikasa shrugged.

"I don't know. What did you guys do before I was here?" Mikasa asked, ruining the mood.

"We were just warming up before you began observing us." Marco's face inched toward hers, daring her in a way. Mikasa had never seen Marco like this, so taunting and tantalizing. "If you want to give Jean his birthday present, why don't you wrap it?" Marco glanced over to the heap of clothes. Mikasa caught on.

Mikasa crawled away from Jean, only to return with condoms and lube that she retrieved from underneath the heap of clothes. Mikasa grinned as she brought the condom up to her mouth, tearing the packet with ease, to reveal the 'wrapping paper' to Jean's present.

Mikasa slid her hand down Jean's abs slowly before yanking Jean forward by the waistband of his pants. As she did, Marco nibbled on Jean's ear, making Jean groan with titillation. Marco's hands slid down and in front Jean's body also, helping Mikasa pull down Jean's unneeded pants, along with his boxers. The two revealed Jean's hardening cock.

Jean let out a gasp as the cool evening air hit his exposed skin. Not even giving Jean a chance to recover, Mikasa slipped the condom on Jean skillfully, pinching the reservoir tip to ensure no air gets trapped in the condom. Jean's member was fully hard at Mikasa's touch. She knew what she was doing.

Marco's hands wandered while his mouth was planted on Jean's neck, giving him hickeys. Marco stopped suckling his neck for a moment, only to take off the rest of his clothing articles. Mikasa observed Marco's actions and felt that she was also wearing too much clothing.

Mikasa shifted back a little, so Jean could get a full view of her stripping. She tore off her jacket, tossing it to the growing lump of clothes. She then gripped the bottom hem of her shirt with both hands, arms crossed, pulling it up over her head in a cutesy way.

Mikasa deliberately poured the lubrication in her hand leisurely to tease Jean even more. A moan was growing up out of Jean's throat at the sight of this.

"Are you sure you want to do this, Mikasa?" Jean looked in Mikasa's dark eyes, looking for an untold answer.

"Yes," Mikasa breathed as she leaned into Jean's face. She was determined to give him the best birthday present after being convinced by Marco. Their lips connected, Jean parted his to let out a moan. Mikasa took the chance to let her tongue graze the inside of Jean's mouth. Jean being preoccupied with the steamy kiss, Mikasa decided it was time to put her lubed-up hand to work.

Mikasa clutched Jean's member and began to stroke it. Down, she gripped the shaft a little. Up, her thumb rubbed the slit. As she worked her hand, her tongue explored the inside of Jean's mouth, prodding his tongue with hers and making swirling motions.

"Damn, Mikasa." Jean broke the kiss to inhale before continuing. Jean let his hands rest on Mikasa's bear sides.

Marco had watched the show in front of him long enough. His aching and clothed cock pressed in Jean's back. But now is not the time to pleasure himself. He needed to step up his game. Maybe being behind Jean was turning out to be a disadvantage. _Or was it?_

Marco swiped the lube, unbeknownst to the other two. Marco squeezed the lubrication onto his own hands. Marco smirked at the thought of what he was doing. His hand glided down Jean's back, smearing the excess lube all over Jean. Marco's hand finally reached its destination: Jean's bum.

Marco held Jean's buttocks up off the ground slightly, making Jean lift himself up a little . Marco then used both hands and spread Jean's ass cheeks for a better view. Marco slid a finger over Jean's entrance playfully.

"Ahh! Stop!" Jean trembled into his touch. Jean's opening was fully visible with his ass stuck up in the air.

"Your body seems like it doesn't want me to stop. Look at how much you try to rut back into my hand, even before I slipped a finger into you." 

Marco decided to let Jean have it. Marco kneaded Jean's tiny hole with one finger while Mikasa sustained Jean's front. Jean writhed between the two.

Marco nudged another finger into Jean. His butt clenched at the abrupt movement. Mikasa let Jean catch his breath again. As Jean panted, Mikasa slipped off her white pants and flung them to the ever-growing pile of clothes beside them.

Jean reached up impulsively and touched her cheek. _God, she was so beautiful._ His hands then wandered down to her covered breasts, massaging them circles. Jean's touch awarded a whimper from Mikasa. Jean pulled Mikasa closer and looped his arms around her back, fumbling with her bra fastening. He finally succeeded, revealing Mikasa's perky breasts.

"Oh my god, Marco!" Jean yelped as Marco surpassed the thought of just two fingers and went ahead and jammed three in. Jean jerked his hips forward toward Mikasa.

"You like that, Jean?" Marco sounded so enticing, even to Mikasa. Marco kept fingering Jean's quivering hole.

All of sudden, Marco stopped pleasuring Jean's anus and stood up on his knees. He beckoned Mikasa over to him with a curling finger. Mikasa did as she was told.

"Mikasa, could you help me wrap the present I was planning to give to Jean?" Marco looked at Mikasa expression for an approval. Although her face gave nothing, Mikasa nodded her head yes. Marco undid his pants and unveiled his own growing erection.

Mikasa looked away for a moment, embarrassed at the sight of another man's genitals, but Marco took Mikasa's face in his palm to meet his again. Marco gave one of his reassuring smiles, comforting Mikasa. Mikasa turned back and grabbed another condom laying beside Jean.

She did the same as she did to Jean, putting the condom on Marco gracefully with her long fingers. Marco let out a groan filled with pleasure in his voice. This time Mikasa took the lubrication and poured it straight onto Marco's dick.

"Mikasa, could you-" Marco opened his mouth from shocking satisfaction, not being able to finish his sentence. Mikasa knew where this was leading. Marco's cock was not fully erect yet, so she was the one who had to do something about it.

Mikasa bent down with her face close to Marco's genitals and gave his cock a quick swipe of tongue to test Marco. Mikasa looked up at Marco with amusement. Mikasa slipped the head into her mouth, wrapping her hand around the shaft. Jean turned around to see Mikasa's head bobbing in Marco's lap.

"I thought I was the one receiving a gift today." Jean crawled towards Mikasa's bottom that was in air as she sucked Marco's cock. "Since we are all giving away presents here on _my_ birthday," Jean gripped Mikasa's thighs and positioned his face near her genitalia.

"No, not there!" Mikasa's face skewed with bliss as her head rose from Marco's lap, trying to get a better look at Jean. Mikasa let in a quick exhale as she trembled. Jean twirled his tongue against her clit, sending waves of pleasure. Marco looked down at the woman in his lap.

"Please," Marco breathed, "Keep going." Mikasa complied and sucked on Marco's head the best she could as Jean worked her backside. Jean poked Mikasa's opening with his tongue, then sticking his tongue in as far as he could, causing Mikasa to gasp.

Marco ran his hands through Mikasa's hair as her head bobbed up and down on him. Her lips were wrapped tightly around Marco's dick, glistening as they slid slowly back and forth on his lube-slickened shaft. After several minutes of putting on a show of swallowing Marco's cock, she let it slide out of her mouth again, moaning from Jean flicking her clit with his tongue.

Jean examined Mikasa's wetness and decided to stick two fingers in and out of her, slowly to make sure he did not hurt her. Jean felt the inside of her walls, moist and smooth.

"Do you like this?" Jean leaned forward to whisper to Mikasa. Marco lifted her head off his own head to allow Mikasa to speak. She nodded her head in agreement. Jean took one moment to remove his fingers from her slippery pussy and place them in her mouth. When she finished sucking her juices from Jean's fingers, he placed them back inside her warm cunt and continued to rub her off. Marco watched the two and also rubbed himself off.

"I think you had enough." Jean glanced over at Marco, awaiting for an answer.

"Yes, let's switch positions." Marco grinned.


	3. What Did We Get Ourselves Into?

**Summary for the Chapter:**

> The moment we have been waiting for!

With Jean in the middle, Mikasa facing his front and Marco facing his back, the trio was almost back in the same position they started from except they were all stark naked. Jean was in Marco's lap while Mikasa was in his.

Mikasa reached down and grabbed Jean's cock, pointing it at her dripping lips as she swung one leg over Jean's hips. Positioning the head of Jean's dick at the opening of her pussy, Mikasa sat down on it, pushing it deep inside herself, letting out a cry.

Marco fondled Jean's rear again, preparing Jean for him. Marco could not wait any longer. He needed Jean. Marco angled himself in front of Jean's anus, gripping his thighs, quickly thrusting inside, and making Jean yelp loudly.

"Marco!" Jean screeched. Tears formed at the corner of Jean's eyes. Mikasa held Jean's head between her hands and kiss the tears away. Marco stayed still, letting Jean recover. Jean soon regained his posture.

Jean's hands were squeezing Mikasa's tits and pinching her nipples as her hips slammed against his. She leaned over as her mouth found Jean's, kissing him deep, their tongues sliding into each other's mouths.

"Can I move now, Jean?" Marco kissed the nape of Jean's neck soothingly. Marco slinked his arms around Jean, thumbing with nipples again.

"Yea-yes." Jean exhaled his words. Being pleasured in all areas, this almost too much for him. For a second, everything seemed so surreal as Mikasa looked at Jean with lustful eyes and Marco rolled his hips into Jean. The three were all a moaning, groaning, whimpering, tangled mess. Soon Mikasa's hips grinded into Jean, matching Marco's pace.

The explicit slapping of skin seemed to echo throughout the maintenance room. Jean gripped Mikasa's hipbones suddenly as he felt a wave of thrill hit him, making Mikasa jolt forward. Jean noticed Mikasa's reaction, and did the same again, to verify it.

"Oh," Jean moaned, "You like that, Mikasa?" As Jean spoke, Marco decided to test Jean too by biting his shoulder. "Ow! Marco!" Jean's face distorted from the exotic pain. Marco thrusted a little harder into Jean than he anticipated. Marco began to see white.

 _Not yet,_ Marco argued with himself internally, _I have to please Jean first._ Marco nipped harder and pinched Jean's nipples firmly. Jean let out a sex-induced growl, not being able to control himself. Jean could feel himself releasing soon as Mikasa kept plunging herself down on Jean's erection.

"Marco!" Jean yelled his name. That was what exactly what Marco wanted to hear. _Polo,_ he joked inside his mind, actually giggling at the thought. Jean looked back at his friend, questioning him for the laughter. To answer, Marco shoved himself deeper inside Jean, making Jean grimace at the pain.

Mikasa's hips moving faster now; lifting herself up to the tip of Jean's cock, and then slamming herself back down forcefully. She was trying to regain Jean's attention so his full focus was her. Her back arched in a way that Jean kept hitting a spot that sent shivers up Mikasa's spine, hopefully please Jean in the process.

I am so close, Mikasa closed her eyes. Mikasa let out a strange wail as her body surged with excitement. Her moaning had stopped as she worked to catch her breath and her head was down as she enjoyed the orgasm running through her, but she continued riding on Jean's dick for his own to come.

"I - I am cumming! I'm CUMMING!" Jean could not handle it anymore. It was time to surrender himself to the most intense orgasm he has ever had. Jean's toes curled as he released himself inside the condom, gasping for air. Jean tried to catch his breath as he rode out the orgasm as long as he could.

Marco followed right after him, releasing his load while his whole body shook with delight. Marco threw his head back, closing his eyes, staying still for a moment. As the panting subsided, the three stared at each other for a moment.

"Happy birthday, Jean." Mikasa kissed Jean again. She got up from Jean's now flaccid cock. She picked off the used condom on Jean's dick.

"Yeah, Happy birthday." Marco beamed as he slowly slid himself out of Jean's hole and stood up, pulling off his condom too. He offered his hand to help Jean up. Suddenly, the three turned the attention toward an unusual noise.

"What was that?" Jean murmured as Marco helped him up. Mikasa quickly grabbed her lump of clothes, shielding her naked body. Marco bent down and gather his clothes up in a hurry. Jean looked around the room suspiciously and felt panic wash over him.

"You dirty pigs." Keith Shadis entered the maintenance room. "Fornication is not allowed here."

_Shit, we got caught._

**Notes for the Chapter:**

> I just really wanted to write a threesome between these characters since I could not find any explicit fanfics with them yet.  
> So how was it? Should I write more smut? Or should I got burn in hell for this?


End file.
